There are various types of human cardiovascular diseases with complicated etiology, among them hypertension, cardiac failure, angina pectoris and arrhythmia are usually encountered. Drugs used in the treatment of cardiac arrhythmia are generally classified into four groups, such as sodium channel blockers, adrenergic blocking agents, potassium channel blockers and calcium channel blockers. Other cardiovascular agents include nitrates, digitalis, anticoagulants, diuretics, and lipid-lowering agents . . . etc. Some patients are simultaneously attacked by at least two types of cardiovascular disease, for instance, patients who suffer from cardiac failure and arrhythmia should not be treated with calcium channel blockers or strong sodium channel blockers with calcium channel blocking activity such quinidine. Patients having both angina pectoris and atrial arrhythmia can be treated with calcium channel blockers which relieve the symptoms of angina pectoris by reducing the oxygen demand of myocardium.
Secoaporphine derivatives such as morphine, codeine are present in Papaveraceae or Sapindaceae plants. The secoaporphine structure is related to that of aminobenzylisoquinoline, which is synthesized in vivo via tyrosine-isoquinoline pathway. Aminobenzylisoquinoline can also be synthesized in the laboratory according to the method of Pachorr in the presence of sodium nitrate. Most secoaporphine derivatives, for instance morphine, codeine, apomorphine are used as narcotic or antiemetic drugs. Secoaporphine derivatives rarely have been reported to exhibit a pharmacological effect on the cardiovascular system.